Smart TNRi iPad glitch experiment

This is a nice experiment by VJFranzK, I believe I know what is going on here, but can you figure it out?

“Can you figure it out? This strange track uses a nonstandard technique to produce sonic glitches at several points through the song. Hint: It’s not changing the tempo ( which I only do at the very end. ) I think I am the first to discover, or film this trick on YouTube? It’s called a Valse because it ( at least begins ) in 12 beat timing.

Sorry my hands are blocking the view in some parts, but I can’t exactly make them transparent This requires multiple fingers to do it well, and can’t easily be done on the Hardware Tenori due to the difference in menu systems.”